1. Field of the Invention
The disclosures discussed herein relate to an imaging device, a control method of the imaging device, and a pixel structure.
2. Description of the Related Art
There are disclosed solid-state imaging devices having improved sensitivity known in the art. Such solid-state imaging devices employ phototransistors configured to amplify an optical current to output the amplified optical current, thereby serving as a photoelectric converters. The solid-state imaging devices having the above-described phototransistors have residual electric charges remaining in a base. The residual electric charges are obtained by reset operations after the output of the amplified optical current. The solid-state imaging devices may thus be able to improve their sensitivity by discharging the residual electric charges remaining in the base (accumulated electric charges in the base that have not been completely discharged when reading).
For example, Japanese Laid-open Patent Publication No. 2013-187527 (hereinafter referred to as “Patent Document 1”) discloses an imaging device with a reduced size and improved light utilization efficiency. The imaging device disclosed in Patent Document 1 includes implanted electrodes insulated by an oxide film to separate pixels. Hence, the imaging device increases optical current amplification by applying a voltage to the implanted electrodes to thereby achieve the reduction in size and the improved light utilization efficiency.
However, the related art solid-state imaging devices have the optical current amplified by the application of the voltage to the implanted electrodes when reading signals, which may increase a time to discharge residual electric charges when resetting relative to the amplification of the optical current when reading.